In 2022, cellular plasticity has been added as a new 'Hallmark of Cancer'. It can be defined as the ability of cancer cells to dynamically modulate biochemical and biomechanical properties in response to intracellular and extracellular stimuli. The plastic nature of the cells is known to be associated with altered heterogeneity, which has been linked with aggressive tumor phenotype contributing to metastasis and therapeutic resistance in different cancers. Recent findings from the lab have emphasized the role of EpCAM, a breast cancer stem cell marker, as a key modulator of cellular plasticity, contributing to radiotherapy resistance in ER/PR+ breast cancer. This motivated us to look at other aspects of plasticity and its role in different therapy resistance models. Currently, our lab is investigating the role of cellular plasticity with an emphasis on the role of EMT-MET hybrid status and metabolic plasticity in targeted therapy resistance in HER2-ve BC model.